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Scoping Reviews: When to Use Them and How to Do Them Well

Scoping reviews have become one of the most popular forms of evidence synthesis. They are used to map the extent and nature of research on a topic, to clarify concepts, to identify the types of evidence available and to find gaps that might justify a full systematic review or new primary research. Their popularity has a downside, though. Many published scoping reviews are scoping reviews in name only. Some are really unsystematic narrative reviews; others are systematic reviews that have been relabelled to avoid quality appraisal. This guide explains what a scoping review is for, when it is the right choice, how to conduct one rigorously and how a source-linked assistant such as Yila can help with the charting of evidence that sits at the heart of the method.

What a scoping review is

A scoping review systematically identifies and maps the available evidence on a broad topic. Like a systematic review, it uses transparent, reproducible methods for searching, selecting and charting studies. Unlike a systematic review, it does not usually aim to answer a narrow question about effectiveness or to synthesise findings into a pooled estimate. Its purpose is descriptive: what research exists, what concepts and methods are used, where and with whom research has been conducted, and where the gaps are.

Formal quality appraisal is optional in most scoping review frameworks, because the aim is to map the literature rather than to judge the strength of evidence for a conclusion.

When to choose a scoping review

Scoping reviews suit several purposes: exploring an emerging field where the volume and nature of research are unclear, clarifying how key concepts or terms are defined and used, identifying the types of evidence and methods used in a field, examining how research has been conducted on a topic, informing the scope of a future systematic review, and identifying gaps to guide research priorities.

They are not the right choice when you want to know whether an intervention works, how large an effect is, or what practice should be. Those questions need a systematic review with appraisal and synthesis.

Use an established framework

Several methodological frameworks guide scoping reviews, building on early work that set out a five-stage process and later refinements that added detail and a consultation stage. Widely used guidance from evidence synthesis organisations provides detailed instructions, and a reporting extension of a major reporting guideline specifies what scoping reviews should report.

Choose a framework, cite it and follow it. This gives your review a recognised structure and helps reviewers and readers judge its rigour.

Develop a protocol

Write a protocol before you begin, setting out the question, eligibility criteria, search strategy, selection process and charting approach. Registering or publishing the protocol increases transparency and reduces the risk of changing methods in response to findings.

Scoping review questions are usually broader than systematic review questions. A common framework uses population, concept and context to define the scope.

Search comprehensively

Searches should be broad and systematic, covering relevant databases, grey literature and other sources such as reference lists and expert contacts. Because scoping reviews aim to map the full range of evidence, they often include diverse study designs and publication types.

Work with an information specialist if possible. Document the search fully so it can be reproduced.

Select studies transparently

Apply eligibility criteria consistently, ideally with two reviewers screening independently, at least for a sample. Because scoping review criteria are often broad, refine them iteratively during a pilot phase and document any changes.

Report the selection process in a flow diagram showing the number of records identified, screened and included, with reasons for exclusion at the full-text stage.

Chart the data

Charting is the scoping review equivalent of data extraction. Develop a charting form that captures the information needed to answer your question, such as author, year, country, population, concept, context, methods and key findings relevant to the review's aims. Pilot the form on a sample of studies and refine it.

Charting can be demanding when studies are numerous and diverse. A source-linked assistant helps: asking Yila how a study defined a concept, which population it involved or what methods it used returns answers linked to the relevant passages. The person charting can confirm each entry quickly, and a second reviewer can check entries by looking at the same passages. This keeps the charting both efficient and verifiable.

Collate and summarise

Present the results in ways that address the review's aims. Common approaches include numerical summaries of study characteristics, such as the distribution of studies by country, year or design, alongside tables and charts. A narrative summary describes the main patterns, concepts and gaps.

Avoid overinterpreting findings. A scoping review shows what research exists, not what it proves. If studies report findings, you can describe them, but be careful not to draw conclusions about effectiveness without appraisal and synthesis.

Consider consultation

Some frameworks include an optional consultation stage, in which stakeholders such as practitioners, patients or policymakers are involved in interpreting findings or identifying gaps. Consultation can increase the relevance and impact of a scoping review, particularly when it is intended to inform practice or research priorities.

Report thoroughly

Follow the relevant reporting guideline. Report the framework used, the protocol, the search strategy, the selection process, the charting approach and the results. Discuss limitations, such as language restrictions, database coverage and the absence of quality appraisal where applicable.

Plan the team and timeline

Scoping reviews are often underestimated. Broad questions can produce thousands of records and hundreds of included studies, and charting diverse evidence takes far longer than many teams expect. Before you begin, estimate the likely volume from pilot searches, agree who will screen and chart, and build a realistic timeline with milestones for searching, screening, charting and writing. Include someone with methodological experience and someone with deep knowledge of the topic. A clear division of labour and regular team meetings to resolve uncertainties keep the review consistent and on schedule.

Avoid common pitfalls

Common pitfalls include using "scoping review" to describe a review that is not systematic, choosing a scoping review when the question requires a systematic review, drawing effectiveness conclusions without appraisal, failing to follow or cite a framework, not publishing a protocol, and charting too little or too much information.

Use scoping reviews wisely

A well-conducted scoping review is a valuable contribution. It can clarify a confused field, reveal neglected populations or settings, and guide the next stage of research. Its value depends on rigour and on choosing it for the right reasons.

Scoping reviews are not shortcuts. They require careful planning, comprehensive searching, transparent selection and thoughtful charting. When used for the right questions and done well, they give researchers, funders and decision-makers a clear map of what is known and where knowledge is still needed.